Spoofing Vulnerability in Microsoft Office Outlook by Microsoft
CVE-2026-21260

7.5HIGH

Key Information:

Vendor

Microsoft
Status
Microsoft 365 Apps For Enterprise
Microsoft Office 2019
Microsoft Office Ltsc 2021
Microsoft Office Ltsc 2024
Vendor
CVE Published:
10 February 2026

What is CVE-2026-21260?

The vulnerability in Microsoft Office Outlook facilitates the exposure of sensitive information to unauthorized actors, potentially enabling spoofing attacks over a network. An unauthorized attacker could exploit this weakness, manipulating the application to impact the integrity and confidentiality of communications. It is crucial to ensure that the latest security updates and patches are applied to mitigate the risks associated with this vulnerability.

Affected Version(s)

Microsoft 365 Apps for Enterprise 32-bit Systems 16.0.1

Microsoft Office 2019 32-bit Systems 19.0.0

Microsoft Office LTSC 2021 32-bit Systems 16.0.1

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE...
vendor-advisorypatch

CVSS V3.1

Score:
7.5
Severity:
HIGH
Confidentiality:
High
Integrity:
None
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.